A natural hip joint may undergo degenerative changes due to a variety of etiologies. When such degenerative changes become so far advanced and irreversible, it may ultimately become necessary to replace a natural hip joint with a prosthetic hip. If the acetabulum needs repair, all remnants of articular cartilage may be removed from the acetabulum and an acetabular prosthesis which will accommodate the head or ball of the hip prosthesis may be affixed to the acetabulum.
The acetabular prosthesis can include an acetabular cup and a bearing that, in combination, cooperate with the head or ball of the hip prosthesis. One suitable material for such an acetabular cup is titanium. Titanium has the benefit of being biocompatible as well as elastic. Elasticity can be an important material characteristic as most acetabular cups need to deform slightly during press-fitting into a prepared acetabulum. However, because titanium is so elastic, the material generally needs to be a predetermined minimum thickness (e.g., about 3.5 mm or larger) in order to accommodate the loads in this area. This minimum thickness either requires the head of the femoral component to be smaller or additional reaming and bone removal to accommodate an acetabular cup having a larger outer diameter. In most cases however, reducing the size of the femoral head is unfavorable as it may increase the risk of dislocation. Moreover, it is desirable to keep reaming and bone removal at a minimum in order to maximize the amount of host bone in the acetabular socket for receipt of the acetabular cup.